diff options
Diffstat (limited to '3rdParty/Boost/src/boost/proto/transform/fold.hpp')
-rw-r--r-- | 3rdParty/Boost/src/boost/proto/transform/fold.hpp | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/proto/transform/fold.hpp b/3rdParty/Boost/src/boost/proto/transform/fold.hpp new file mode 100644 index 0000000..b459bc6 --- /dev/null +++ b/3rdParty/Boost/src/boost/proto/transform/fold.hpp @@ -0,0 +1,338 @@ +#ifndef BOOST_PP_IS_ITERATING + /////////////////////////////////////////////////////////////////////////////// + /// \file fold.hpp + /// Contains definition of the fold<> and reverse_fold<> transforms. + // + // Copyright 2008 Eric Niebler. Distributed under the Boost + // Software License, Version 1.0. (See accompanying file + // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + + #ifndef BOOST_PROTO_TRANSFORM_FOLD_HPP_EAN_11_04_2007 + #define BOOST_PROTO_TRANSFORM_FOLD_HPP_EAN_11_04_2007 + + #include <boost/version.hpp> + #include <boost/preprocessor/cat.hpp> + #include <boost/preprocessor/iteration/iterate.hpp> + #include <boost/preprocessor/arithmetic/inc.hpp> + #include <boost/preprocessor/arithmetic/sub.hpp> + #include <boost/preprocessor/repetition/repeat.hpp> + #include <boost/fusion/include/fold.hpp> + #include <boost/proto/proto_fwd.hpp> + #include <boost/proto/fusion.hpp> + #include <boost/proto/functional/fusion/reverse.hpp> + #include <boost/proto/traits.hpp> + #include <boost/proto/transform/call.hpp> + #include <boost/proto/transform/impl.hpp> + + namespace boost { namespace proto + { + namespace detail + { + template<typename Transform, typename Data> + struct as_callable + { + as_callable(Data d) + : d_(d) + {} + + template<typename Sig> + struct result; + + #if BOOST_VERSION >= 104200 + + template<typename This, typename State, typename Expr> + struct result<This(State, Expr)> + { + typedef + typename when<_, Transform>::template impl<Expr, State, Data>::result_type + type; + }; + + template<typename State, typename Expr> + typename when<_, Transform>::template impl<Expr &, State const &, Data>::result_type + operator ()(State const &s, Expr &e) const + { + return typename when<_, Transform>::template impl<Expr &, State const &, Data>()(e, s, this->d_); + } + + #else + + template<typename This, typename Expr, typename State> + struct result<This(Expr, State)> + { + typedef + typename when<_, Transform>::template impl<Expr, State, Data>::result_type + type; + }; + + template<typename Expr, typename State> + typename when<_, Transform>::template impl<Expr &, State const &, Data>::result_type + operator ()(Expr &e, State const &s) const + { + return typename when<_, Transform>::template impl<Expr &, State const &, Data>()(e, s, this->d_); + } + + #endif + + private: + Data d_; + }; + + template< + typename State0 + , typename Fun + , typename Expr + , typename State + , typename Data + , long Arity = arity_of<Expr>::value + > + struct fold_impl + {}; + + template< + typename State0 + , typename Fun + , typename Expr + , typename State + , typename Data + , long Arity = arity_of<Expr>::value + > + struct reverse_fold_impl + {}; + + #define BOOST_PROTO_CHILD_N_TYPE(N)\ + BOOST_PP_CAT(proto_child, N)\ + /**/ + + #define BOOST_PROTO_FOLD_STATE_TYPE(Z, N, DATA) \ + typedef \ + typename when<_, Fun>::template impl< \ + typename result_of::child_c<Expr, N>::type \ + , BOOST_PP_CAT(state, N) \ + , Data \ + >::result_type \ + BOOST_PP_CAT(state, BOOST_PP_INC(N)); \ + /**/ + + #define BOOST_PROTO_FOLD_STATE(Z, N, DATA) \ + BOOST_PP_CAT(state, BOOST_PP_INC(N)) \ + BOOST_PP_CAT(s, BOOST_PP_INC(N)) \ + = typename when<_, Fun>::template impl< \ + typename result_of::child_c<Expr, N>::type \ + , BOOST_PP_CAT(state, N) \ + , Data \ + >()( \ + proto::child_c<N>(e) \ + , BOOST_PP_CAT(s, N) \ + , d \ + ); \ + /**/ + + #define BOOST_PROTO_REVERSE_FOLD_STATE_TYPE(Z, N, DATA) \ + typedef \ + typename when<_, Fun>::template impl< \ + typename result_of::child_c< \ + Expr \ + , BOOST_PP_SUB(DATA, BOOST_PP_INC(N)) \ + >::type \ + , BOOST_PP_CAT(state, BOOST_PP_SUB(DATA, N)) \ + , Data \ + >::result_type \ + BOOST_PP_CAT(state, BOOST_PP_SUB(DATA, BOOST_PP_INC(N))); \ + /**/ + + #define BOOST_PROTO_REVERSE_FOLD_STATE(Z, N, DATA) \ + BOOST_PP_CAT(state, BOOST_PP_SUB(DATA, BOOST_PP_INC(N))) \ + BOOST_PP_CAT(s, BOOST_PP_SUB(DATA, BOOST_PP_INC(N))) \ + = typename when<_, Fun>::template impl< \ + typename result_of::child_c< \ + Expr \ + , BOOST_PP_SUB(DATA, BOOST_PP_INC(N)) \ + >::type \ + , BOOST_PP_CAT(state, BOOST_PP_SUB(DATA, N)) \ + , Data \ + >()( \ + proto::child_c<BOOST_PP_SUB(DATA, BOOST_PP_INC(N))>(e) \ + , BOOST_PP_CAT(s, BOOST_PP_SUB(DATA, N)) \ + , d \ + ); \ + /**/ + + #define BOOST_PP_ITERATION_PARAMS_1 (3, (1, BOOST_PROTO_MAX_ARITY, <boost/proto/transform/fold.hpp>)) + #include BOOST_PP_ITERATE() + + #undef BOOST_PROTO_REVERSE_FOLD_STATE + #undef BOOST_PROTO_REVERSE_FOLD_STATE_TYPE + #undef BOOST_PROTO_FOLD_STATE + #undef BOOST_PROTO_FOLD_STATE_TYPE + #undef BOOST_PROTO_CHILD_N_TYPE + + } // namespace detail + + /// \brief A PrimitiveTransform that invokes the <tt>fusion::fold\<\></tt> + /// algorithm to accumulate + template<typename Sequence, typename State0, typename Fun> + struct fold : transform<fold<Sequence, State0, Fun> > + { + template<typename Expr, typename State, typename Data> + struct impl : transform_impl<Expr, State, Data> + { + /// \brief A Fusion sequence. + typedef + typename remove_reference< + typename when<_, Sequence>::template impl<Expr, State, Data>::result_type + >::type + sequence; + + /// \brief An initial state for the fold. + typedef + typename remove_reference< + typename when<_, State0>::template impl<Expr, State, Data>::result_type + >::type + state0; + + /// \brief <tt>fun(d)(e,s) == when\<_,Fun\>()(e,s,d)</tt> + typedef + detail::as_callable<Fun, Data> + fun; + + typedef + typename fusion::result_of::fold< + sequence + , state0 + , fun + >::type + result_type; + + /// Let \c seq be <tt>when\<_, Sequence\>()(e, s, d)</tt>, let + /// \c state0 be <tt>when\<_, State0\>()(e, s, d)</tt>, and + /// let \c fun(d) be an object such that <tt>fun(d)(e, s)</tt> + /// is equivalent to <tt>when\<_, Fun\>()(e, s, d)</tt>. Then, this + /// function returns <tt>fusion::fold(seq, state0, fun(d))</tt>. + /// + /// \param e The current expression + /// \param s The current state + /// \param d An arbitrary data + result_type operator ()( + typename impl::expr_param e + , typename impl::state_param s + , typename impl::data_param d + ) const + { + typename when<_, Sequence>::template impl<Expr, State, Data> seq; + detail::as_callable<Fun, Data> f(d); + return fusion::fold( + seq(e, s, d) + , typename when<_, State0>::template impl<Expr, State, Data>()(e, s, d) + , f + ); + } + }; + }; + + /// \brief A PrimitiveTransform that is the same as the + /// <tt>fold\<\></tt> transform, except that it folds + /// back-to-front instead of front-to-back. It uses + /// the \c _reverse callable PolymorphicFunctionObject + /// to create a <tt>fusion::reverse_view\<\></tt> of the + /// sequence before invoking <tt>fusion::fold\<\></tt>. + template<typename Sequence, typename State0, typename Fun> + struct reverse_fold + : fold<call<_reverse(Sequence)>, State0, Fun> + {}; + + // This specialization is only for improved compile-time performance + // in the commom case when the Sequence transform is \c proto::_. + // + /// INTERNAL ONLY + /// + template<typename State0, typename Fun> + struct fold<_, State0, Fun> : transform<fold<_, State0, Fun> > + { + template<typename Expr, typename State, typename Data> + struct impl + : detail::fold_impl<State0, Fun, Expr, State, Data> + {}; + }; + + // This specialization is only for improved compile-time performance + // in the commom case when the Sequence transform is \c proto::_. + // + /// INTERNAL ONLY + /// + template<typename State0, typename Fun> + struct reverse_fold<_, State0, Fun> : transform<reverse_fold<_, State0, Fun> > + { + template<typename Expr, typename State, typename Data> + struct impl + : detail::reverse_fold_impl<State0, Fun, Expr, State, Data> + {}; + }; + + /// INTERNAL ONLY + /// + template<typename Sequence, typename State, typename Fun> + struct is_callable<fold<Sequence, State, Fun> > + : mpl::true_ + {}; + + /// INTERNAL ONLY + /// + template<typename Sequence, typename State, typename Fun> + struct is_callable<reverse_fold<Sequence, State, Fun> > + : mpl::true_ + {}; + + }} + + #endif + +#else + + #define N BOOST_PP_ITERATION() + + template<typename State0, typename Fun, typename Expr, typename State, typename Data> + struct fold_impl<State0, Fun, Expr, State, Data, N> + : transform_impl<Expr, State, Data> + { + typedef typename when<_, State0>::template impl<Expr, State, Data>::result_type state0; + BOOST_PP_REPEAT(N, BOOST_PROTO_FOLD_STATE_TYPE, N) + typedef BOOST_PP_CAT(state, N) result_type; + + result_type operator ()( + typename fold_impl::expr_param e + , typename fold_impl::state_param s + , typename fold_impl::data_param d + ) const + { + state0 s0 = + typename when<_, State0>::template impl<Expr, State, Data>()(e, s, d); + BOOST_PP_REPEAT(N, BOOST_PROTO_FOLD_STATE, N) + return BOOST_PP_CAT(s, N); + } + }; + + template<typename State0, typename Fun, typename Expr, typename State, typename Data> + struct reverse_fold_impl<State0, Fun, Expr, State, Data, N> + : transform_impl<Expr, State, Data> + { + typedef typename when<_, State0>::template impl<Expr, State, Data>::result_type BOOST_PP_CAT(state, N); + BOOST_PP_REPEAT(N, BOOST_PROTO_REVERSE_FOLD_STATE_TYPE, N) + typedef state0 result_type; + + result_type operator ()( + typename reverse_fold_impl::expr_param e + , typename reverse_fold_impl::state_param s + , typename reverse_fold_impl::data_param d + ) const + { + BOOST_PP_CAT(state, N) BOOST_PP_CAT(s, N) = + typename when<_, State0>::template impl<Expr, State, Data>()(e, s, d); + BOOST_PP_REPEAT(N, BOOST_PROTO_REVERSE_FOLD_STATE, N) + return s0; + } + }; + + #undef N + +#endif |